Which characteristic of high carbon steel makes it suitable for tools?

High carbon steel is known for its significant hardness and ability to maintain a sharp edge, making it an ideal material for manufacturing tools such as chisels, knives, and cutting implements. The high carbon content increases the hardness of the steel, allowing it to withstand wear and tear when used in cutting or drilling applications.

Additionally, the hardening process that high carbon steel undergoes enhances its strength and durability, enabling tools to perform precision tasks effectively. This hardness is essential for tools that require cutting or shaping materials, as it reduces the likelihood of deformation during use.

The other characteristics listed do not provide the same level of suitability for tool-making. Softness would lead to tools that cannot retain an edge and would quickly become ineffective. Lightweight properties might be beneficial in some contexts but do not contribute to durability and cutting ability. Rust-proof features, while useful in certain environments, are not inherent properties of high carbon steel, which typically requires additional treatment to enhance corrosion resistance.